nothing isnt nothing, nothing is something- its empty space, going through time.... that is, within your idea of what existence is
it is possible that existence is exactly as you said... and it probably is something very similar.. matter and energy residing wihin an infinite space and eternal time..
the questions about "what comes after that" arent to be circular.. but to tryt o get you to see the idea that "everythin has to cme from somethign"..
even existence itself
you are contradicting yourself, aquinas argument went something like this, nothing cannot exist for if nothing ever existed something never would, since we are here we can conclude that something does exist and has always existed. Why does something exist rather then nothing, well, as he put it somethings essence must be to exist, that is, the exists for which its essence is solely to exist.
when you say eternal you cant say everything needs a creator, because for one eternal nullifies that notion, it is endless time, no beginning no end, no cause no effect it negates causation. Then even if i grant you that somethign always needs a creator we get into a infinite regress of creators. That is, who is the creators creator and so on, thus making the argument senseless and failing basic logic, ie not possible, not true everything does not need a creator. Everything does not need to be eternal, although i believe it may be and infinite does not exist in real life, its a concept.
Everything does not have to come from something, you really have two options, somethign always existed, or something always existed. Energy can neither be created nor destroyed, a law i put my money on that. No god needed, no further questions. specifically ones about whats outside or other inane questions like what came before time?
paradoxical questions that make no sense. Its also an assumption that we have the tools to understand the universe, something i think is unfounded.